The Laboratories for Reproductive Biology (LRB) proposes to continue a multidisciplinary program for international research and training in reproductive biology with a focus on research leading to contraceptive development. Ongoing collaborations will be continued with scientific institutions in Brazil, Chile, China and Kenya; one new collaboration in India is proposed. The program is designed to 1) enhance research on contraceptive development in the United States, and 2) encourage scientists from developing nations to contribute to research in contraceptive development and advance knowledge in support of populations policies appropriate for their home countries and established international guidelines. It is intended that the training program will produce domestic and international investigators much needed to further our understanding of molecular mechanisms regulating reproductive functions and thereby provide the basis on which to develop improved methods of fertility regulation. Ultimately the goal of the training program is to attack the global problem of overpopulation and its adverse effects on the health and well being of humans. The program provides training in five interrelated areas: 1) regulation of gonadotropin secretion, 2) molecular mechanisms regulating spermatogenesis, 3) reproductive steroid hormone regulation of gene expression, 4) regulation of sperm maturation, 5) fertilization and implantation. The North Carolina training faculty consists of ten members in the Laboratories for Reproductive Biology at the University of North Carolina at Chapel Hill, one adjunct member at North Carolina State University in Raleigh and two adjunct members at the National Institute of Environmental Health Sciences in North Carolina's Research Triangle Park. International collaborators include faculty and trainees in five countries at seven research institutions investigating aspects of reproductive biology related to contraceptive development. The program includes 1) research training for predoctoral and postdoctoral students from the foreign institutions at the Universities in North Carolina, centered in the laboratories of the primary preceptors; 2) visits to the laboratories of U.S. preceptors by participating faculty members from abroad to enhance collaborative research in contraceptive development; 3) in-country visits by U.S. faculty members to conduct training sessions in the cooperating institutions abroad; and 4) research support for trainees returning to their home countries to establish projects that will form the basis for long-term collaborations between the foreign institutions and the LRB.